2008

Left: Linear exposure control maps intensity evenly.
Right: Logarithmic exposure control maps most intensities to low and mid tones.
Tips:
■ If the primary lighting from your scene comes from standard lights (rather
than photometric lights), use the Logarithmic exposure control and turn
on Affect Indirect Only.
■ Use Automatic exposure control for rendering still images. This method
is also useful for first-draft renderings.
■ Use Logarithmic exposure control for animations with a moving camera.
(Automatic and Linear exposure control with a moving camera can cause
excessive flickering.)
■ For rendering high-dynamic-range images with mental ray, use the mr
Photographic exposure control.
■ For outdoor scenes that use the Daylight system, turn on the Exterior toggle
to prevent overexposure.
Exposure and Attenuation for Standard Lights
When you use standard lights that are not attenuated, renderings tend to have
a low dynamic range, because light intensities don't vary greatly across the
scene. In this situation, adjusting light values might be all you need to do to
get a good rendering.
On the other hand, when lights are attenuated the illumination might be too
bright on near surfaces or too dim on distant surfaces. In this situation, the
Automatic exposure control can help, because it adjusts the larger dynamic
range of the (simulated) physical scene, into the smaller dynamic range of the
display.
Exposure Controls | 6533